Rechargeable battery unit



FIG. 1 is a perspective view of a rechargeable battery unit showing the new design;

FIG. 2 is a front view of a rechargeable battery unit thereof;

FIG. 3 is a back view of a rechargeable battery unit thereof;

FIG. 4 is a left side view of a rechargeable battery unit thereof;

FIG. 5 is a right side view of a rechargeable battery unit thereof;

FIG. 6 is a top plan view of a rechargeable battery unit thereof; and,

FIG. 7 is a bottom view of a rechargeable battery unit thereof. 

CLAIM I claim the ornamental design for a rechargeable battery unit, as shown and described. 